I am in the middle of stripping the paint off my 64 wagon and the roof had a lot of deep surface rust. I am sanding the paint off with 36 grit paper (very little pressure) and then hitting it with 50 and 80 grit to get it all cleaned off and smooth. There are lots of black spots where the rust was and I would like to get it off rather than putting some kind of a rust converter on to it and leaving it. Some of it I have been able to get rid of just by sanding with the 80 grit a little more, but some is a little deeper and I don't want to sand so much that it weakens the metal. I have heard of some guys using acid mixture to get the rust out?? The car will be a driver and I want the paint to last as long as possible. Anyone out there had experience with this type of work? If so, let me know the pros and cons and what has worked best for you. Thanks, Erik

There are several "rust converter" products available, the liquid looks like milk, and is supposed to convert the rust to black "primer". You have to be careful with following the instructions, and it's still a crapshoot.

If the rust converter is applied too freely, an acid surface will remain.
If an insufficient amount is used, not all the rust will be converted and residual rust will remain and form the starting point for new corrosion.

I tried it in some places that sound just like yours and found that in most
cases it worked fine, a couple of them rust started again under the gray primer that I applied over it (never painted that one, sold it in primer.

Eastwood has a liquid that "disolves" rust, never tried that but would love to hear from someone that has.

I have used the Eastwood Rust Converter. It leaves a Zinc Phosphate surface on the metal. I did use it after thoroughly working the pitted areas with a brass wire wheel. I don't think any of these products will wipe out heavy scale. Best way is to mechanical clean [blast, wire wheel or sand (last resort)] until darn close to nothing left, then chemical treat for whatever micro pores of oxidation may be left. When using the converters, you have to neutralize them with a water wash and solvent clean as directed on the instructions.

I believe some of the more experienced body men on TC have said to use naval jelly.

I've used naval jelly, phosphoric acid, POR-15 Metal Ready, etc


I don't believe in any of the converter products.

I wouldn't trust anything that covers up the rust. I had surface rust problems with my 71. I used an 80 grit DA, a wire wheel on a small grinder and the stubborn spots left, I used a small home owner sand blaster. I was careful not to get the medal hot with the sand or wire wheel. I never had any warping problems. I then used etching primer, filler primer to fill the small holes left by the rust, blocked it all out several times, then base/clear. The car is straight and the rust never came back.
http://www.chevelles.com/showroom/data/500/71.jpg

I used a small sand blast gun that I had borrowed. It had a small container on it for the sand and an air hose connect. You just press the rubber covered nozzel against the rust spot and shoot. All sand was directed right at the spot. It worked quite well. I initially got it to clean all the butt weld joints on the quarters after welding. The fellow I borrowed it from is no longer around so I can't even find out the name of this gun, hopefully someone here has used one and will know. I think it would do the job for you

Remove any loose rust scale with 80 grit paper. Then proceed to use navel jelly.
Work the navel jelly in with a red scuff pad or steel wool. When working with the jelly keep it WET, do not let it dry on the surface.

Navel jelly does NOT convert the rust into some funky chemical like a converter, it removes the rust leaving behind CLEAN metal. You might find that you need to apply the jelly twice to remove the deep rooted rust.
Once you are happy with the process proceed to clean the metal with warm soapy water. That will remove any residue still left behind.
Then allow to air dry or better yet blow dry it. Then da sand the metal with 80 grit and apply 2 wet coats of epoxy primer.

I used Henry's Scale and Rust Remover before. Pour it on, it ate the surface rust clean off, left shiny metal. Absolutely no rust at all left. It's made for cleaning out industrial cooling systems, but works wonders on rusty metal too. ;) Be careful, it cleans concrete really good, too. :D